The lesson "The Change of Baking Soda and White Vinegar" is the second volume of the sixth grade of primary school science, Unit 2 "The Change of Material". Some types of chemical changes and their accompanying phenomena are introduced in detail. Students study various chemical changes by observing phenomena, making assumptions, looking for evidence and drawing conclusions, and sum up the main characteristics of chemical changes: producing new substances. This experiment includes baking soda and white vinegar.

Teaching objectives:

Cognitive goal:

1, baking soda and white vinegar will react chemically? Produce new substances.

2. Carbon dioxide is a gas with special properties.

Skill objectives:

1. Through observation, experiment, analysis and reading materials, we can draw a correct conclusion.

2. Cultivate students' hands-on inquiry ability through simulation experiment and observation.

Emotional goals:

1, understand that only enough evidence can make a correct judgment, and draw a scientific conclusion requires strict logical reasoning.

2. Cultivate students' correct scientific attitude and spirit.

Teaching methods:

According to the age and thinking characteristics of students with strong curiosity and thirst for knowledge, we should give full play to the characteristics of experimental inquiry in science courses, combine experimental inquiry with inspiration and induction, and guide students to participate in the whole process of knowledge formation. Pay attention to connecting with practice, stimulate students' interest, and combine multimedia to let students know on the basis of perception.

Legal learning guidance:

Through experimental observation, analysis and discussion, this course teaches students to be good at thinking, observing and doing things, thus cultivating students' ability of observation, experimental inquiry and phenomenon analysis. Learn to draw correct conclusions through observation, experiment, analysis and reading materials.

Teaching focus:

Observe and explain the changes of baking soda and vinegar.

Teaching difficulties:

Analyze the substances produced after the changes of baking soda and vinegar.

Teaching preparation:

Baking soda, white vinegar, glasses, glass pieces, candles, matches, white paper, etc.

Teaching time: one class hour.

Teaching process:

(1) import

Students, who knows who Qing Liu is? Do you like him? Tell me why you like him. (Guide students to get a preliminary understanding of Qing Liu)

In fact, teachers can also do magic. Do you want to see the teacher do magic tricks for everyone? Teacher, here are two bottles of mineral water (including a bottle of soda water). Please read it carefully (students can have a taste). Have you ever seen red mineral water? The teacher will use magic to turn it into red mineral water. Do the students believe it?

Demonstration: Pour soda water into a cup soaked with phenolphthalein solution. When soda water is mixed with phenolphthalein solution, the solution turns red. )

In fact, the teacher's magic just now used a mixture of two substances? Something has changed between them? A new red substance was produced. Isn't this magic? Do you want to learn? Whether you want to learn depends on your classmates' performance in class in the future. If everyone can actively think, imagine, answer questions, operate, experiment, observe and record, the teacher will definitely teach you this magic after class? Okay？ In this class, the teacher will work with the students to study the changes after the two substances are mixed.

Display items: baking soda and white vinegar. Look at these two substances. Do you know what they are? How did you know it was white vinegar and baking soda? Observing labels is also a good way to know things. )

In this class, the teacher will study the changes of baking soda and white vinegar with his classmates.

(2) Show the self-study outline

1. Please observe these two substances carefully and make experimental records. Teacher: Here, the teacher should first remind the students that we can't directly touch, smell and taste substances without knowing whether they are harmful to our health. You can only feel its taste through the bottle, and you must never taste it. Understand? Now, the teacher has prepared these two materials for each group. Please observe in your own way and see which group finds the most! )

The taste of white vinegar is very sour, a little blunt? It feels good. Baking soda, like flour, is thicker than flour? It's all small white particles. )

2. If white vinegar and baking soda are mixed, what mixing methods do we have? (3) method. The first one is to put Susie in a beaker first? After pouring white vinegar; The second is to pour white vinegar first, then baking soda; The third is to pour baking soda and white vinegar into the beaker at the same time. Generally speaking, our mixing ratio is a baking soda? Three portions of white vinegar)

3. What happens when white vinegar and baking soda are mixed together? (bubble generation)

4. What can white vinegar and baking soda prove together? What should I do? (Experimental proof)

(3) Group communication and display

(Teachers properly guide)

(D) Students experiment in groups

Teacher: Please experiment according to your own experimental plan, and experiment boldly. When white vinegar reacts with baking soda, you can stir it with a wooden stick instead of shaking it left and right with a gas container. When not stirring, cover the gas container with glass sheets. Record the experimental phenomena on the record card. Compare which group observed carefully and found more phenomena. Teachers instruct students to observe and record phenomena. )

(5) Report the exchange experiment phenomenon.

1. Each group will tell you your findings.

2. Different mixing methods? Are we observing the same phenomenon?

(6) Verify what gas they produce after mixing.

1. In the experiment, we saw that white vinegar and baking soda would produce bubbles when mixed. Can the gas in the bubble be air? (Students guess)

2. How to prove whether it is air?

3. Teacher's demonstration: Match burning experiment

(1) After the experiment, observe an empty bottle and a bottle filled with carbon dioxide. Are they different?

(2) (Teacher's demonstration) Observe the phenomenon of lit matches in the air, and then observe the phenomenon of putting lit matches into a bottle filled with carbon dioxide after the experiment. What happened to the lighted match?

(3) What did you find in the experiment just now?

(4) What properties did we find in this experiment just now? (It is heavier than air and does not support combustion) Can we infer what gas this is based on these two properties?

(7) Discussion: What does this experiment show?

Summary: Today, we did an interesting mixed experiment. By mixing baking soda and white vinegar, we produce gaseous carbon dioxide, which is an interesting chemical change compared with mixing beans and sand.

(8) Design of blackboard writing

Changes of baking soda and white vinegar

Baking soda+white vinegar = carbon dioxide gas (new substance)

(mixing) (gas) (chemical change)